The present invention relates to monotube strut assemblies, and more particularly to a floating rod guide for a monotube strut.
A strut is a type of damper that is used in vehicle suspensions as both a damping device for providing shock absorbing functions and as part of the suspension""s load-bearing structure. Monotube gas-charged dampers are known wherein a piston with a connected piston rod is slidably carried in a fluid-filled tube with a separate piston called a gas cup slidably carried in the tube on an opposite side of the piston from the rod. The gas cup separates a compressible gas charge from the fluid within the damper. It is known that monotube gas-charged dampers exhibit desirable performance characteristics when used in some suspension assemblies.
Typically, the generic monotube strut design configuration is produced primarily as an aftermarket replacement damper, although limited original equipment (OEM) applications have been implemented. The prior art device generally includes a bearing mechanism that includes a combination of a polytetrafluoroethelyne laminated plain bearing and a grease lubricant. In some applications performance advantages of high pressure monotube dampers are well known and therefore, the use of such devices without restriction would be desirable. However, in applying a monotube gas-charged strut in an OEM application, extended durability requirements lead to restrictions in the use of such devices, particularly in applications involving larger and heavier vehicles that operate with resultant increased side loading. In particular, the bearings in such a strut must be assembled and maintained in a straight and true fashion in order to obtain to the bottom of the unit. A cavity of a floating rod guide in this application may get packed with the iron particles, and lose its ability to float. Again this leads to premature rod wear and high damper axial friction.
The present invention is a guide assembly for a rod of a motor vehicle strut. The guide assembly comprises a rod guide, a seal cover, and a retainer. The seal cover engages the rod guide, and defines an area therebetween. The retainer is engaged with the seal cover. A first O-ring is disposed between the seal cover and the rod guide, and a second O-ring is disposed between the rod guide and the retainer.
Accordingly, it is an object of the present invention to provide a guide for a rod of a motor vehicle strut of the type described above which has acceptable force and friction levels.
Another object of the present invention is to provide a rod guide of the type described above which reduces the incidence of premature rod wear.
Still another object of the present invention is to provide a rod guide of the type described above which is acceptable for use in active struts, particularly those that use magneto-rheologic fluid.
The foregoing and other features and advantages of the invention will become further apparent from the following detailed description of the presently preferred embodiments, read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the invention rather than limiting, the scope of the invention being defined by the appended claims and equivalents thereof.